Contemporary Amperex Technology Co., Ltd.

Longfei Yang

Limei Yang

Xiaomei Liu

Yongshou Lin

Fenggang Zhao

Jiang Liu

Guobao Wang

This application provides a method for capacity recovery of lithium-ion secondary battery. The method includes the following steps:

Method for capacity recovery of lithium-ion secondary battery

An electrode assembly and a lithium-ion battery are described. The electrode assembly includes a positive electrode plate, a separator, and a negative electrode plate, where the negative electrode plate includes a negative electrode current collector and a negative electrode active substance layer, the negative electrode plate further includes a lithium metal layer, the lithium metal layer is formed by a plurality of regular or irregular strip-shaped lithium-rich regions, and the plurality of lithium-rich regions present a discontinuous pattern of spaced distribution in a length direction of the negative electrode plate. The electrode assembly further satisfies that: negative electrode capacity per unit area/positive electrode capacity per unit area=1.2 to 2.1 and negative electrode capacity per unit area/(positive electrode capacity per unit area+capacity of the lithium metal layer on the surface of the negative electrode active substance layer per unit area× 80%)≥ 1.10.

Electrode assembly and lithium-ion battery

A lithium-ion secondary battery includes a negative electrode sheet including a negative electrode current collector and a negative electrode film disposed on a surface of the negative electrode current collector and containing a negative active material, a positive electrode sheet including a positive electrode current collector and a positive electrode film disposed on a surface of the positive electrode current collector and containing a positive active material, and an electrolytic solution including lithium iodide, a lithium salt, a solvent, and an additive. A coating weight per unit area, CW/S, of the positive electrode film satisfies CW/S=((CW/S)×b×C/CB−m×X×(199 mAh/g)/S)/(C×a).

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Ningde, China

Longfei Yang